High School Mathematics - 2 10.18 Trignometry Review

Function

0^{o}

30°

45°

60°

90°

sin

Ö0/2

Ö1/2

Ö2/2

Ö3/2

Ö4/2

cos

Ö4/2

Ö3/2

Ö2/2

Ö1/2

0

tan

0

Ö3/3

1

Ö3

undefined

sec

1

2Ö3/3

Ö2

2

undefined

csc

undefined

2

Ö2

2Ö3/3

1

cot

undefined

Ö3

1

Ö3/3

0

sin

cos

tan

0

0

1

0

90

1

0

infinity

180

0

-1

0

270

-1

0

infinity

Functions of angles in all quadrants in terms of those in quadrant 1

-A

90^{0} ± A P/2 ± A

180^{0} ± A P ± A

270^{0} ± A 3P/2 ± A

360^{0} ± A 2P ± A

sin

-sinA

cos A

±sin A

-cosA

±sin A

cos

cos A

±sin A

-cos A

±sin A

cos A

tan

-tan A

±cot A

± tan A

±cot A

±tan A

csc

-csc A

sec A

± csc A

-sec A

±csc A

sec

sec A

± csc A

-sec A

±csc A

sec A

cot

-cot A

± tan A

± cot A

±tan A

± cot A

Q 1: In triangle ABC , if 2 cos A/a + cos B/b + 2 cos C/c = a/bc + b/ca. find angle A 30 degrees 45 degrees 90 degrees

Q 2: Find the angle in radian through which a pendulum swings if its length is 75 cm and the tip describes an arc of length 10 cm 2/15 3/15 4/15

Q 3: In triangle ABC, if b = 6, c = 4, cos A = 1/12, find a 4 3^{1/2} 4.3^{1/2}

Q 4: Find the angle in radian through which a pendulum swings if its length is 75 cm and the tip describes an arc of length 15 cm 2/5 1/5 1/3

Q 5: A person standing on the bank of a river, observes that the angle subtended by a tree on the opposite bank is 60 degrees, when he retires 40 metres from the bank, he finds the angle to be 30 degrees. Find the height of the tree. 20 metres 64 metres 34 metres

Q 6: The elevation of a tower at a point 60 metres from it is cot^{-1}3/5 Obtain the height of the tower. 110 metres 45 metres 100 metres

Q 7: The angular elevation of a tower from a point is 30 degrees at a point in a horizontal line to the foot of the tower and 100 metres near it is 60 degrees, find the distance of the first point from the tower. Answer:

Q 8: A vertical flagstaff stands on a horizontal plane from a point distant 150 metres from its foot, the angle of elevation of its top is found to be 30^{o}, find the height of the flagstaff. 100.4 metres 113.4 metres 100 metres

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Question 10: This question is available to subscribers only!